Planar tiles are adhered to a wall, floor or ceiling using an adhesive. Separate spacers are generally placed between the tiles during installation, to provide alignment and spacing. The spaces between the tiles are subsequently sealed with a water-resistant grout to prevent water from penetrating beyond the tiles into the supporting wall and structure. Tiles are typically arranged in uniform patterns.
Ceramic has been the material of choice for millennia of tile fabrication owing to its low material cost, water resistance and acceptance of colorful, hard surface finishes. Disadvantages of ceramic tiles include the inefficiencies arising from their weight, brittleness and their thru-hardness. Heavy ceramic tiles are costly to transport. They require specialized equipment to cut, and in the process are prone to break and create hazardous, airborne silica dust. In contrast, the fabrication of plastic tiles by injection molding allows for tiles that are relatively light, are easily cut with conventional wood cutting tools, have high impact strength, and can be formulated to provide flame retardant and anti-microbial properties that are inherent to ceramic tiles. The recent development of clear, high-gloss, hard coatings for plastics and of digital printing on plastic surfaces now permits durable and colorful plastic tiles to be produced. All the known attributes of injection molded plastic parts, including shape, texture, raised and relieved features, molded-in color and clarity, are easily incorporated into a plastic tile. Where necessary, plastic tiles can be deformed to contour around a curved surface, something not possible with rigid ceramic tiles.
This Invention discloses a means that allows the tiles to self-align and self-space during their installation, and includes integral aligning and spacing features on the tiles that replace the need for separate spacers typically required when installing conventional ceramic tiles. This Invention can be incorporated into both ceramic and plastic tiles, although the plastic injection molding process ensures that these features are accurately produced. Similarly, this Invention can be incorporated into driveway/walkway/deck pavers to facilitate alignment in straight-laid or running bond patterns.
The prior art includes a considerable number of interlocking floor and wall tiling systems as well as interlocking, engineered wood strip-flooring. All of these inventions focused on a desire to have the tiles or strip-flooring connect with each other while they were being aligned with each other. Interlocking flooring and decking systems typically “float” on the sub-floor, which allows for thermal expansion and contraction of the materials throughout the seasons, while ensuring they remain tightly connected. The prior art plastic floor and wall tiling systems included “male” features on two sides to mate with “female” features on the remaining two sides. The female features were typically located on the underside of the tile to cover the projecting male features. The strip-flooring systems had a male (or tongue) feature that engaged with a female (or groove) feature on the opposite side. In all cases, these interlocking features ensured that the tiles were kept tightly fitted. However, a consistent problem existed with all of these prior art systems in that the interlocking features prevented the tiles from being continuously installed in all four directions from a fixed tile. A layout that calls for a particular pattern to be in the center of the floor or wall requires that the remaining tiles be aligned outward in all directions from this central feature. The tiles on the back wall of a bathtub surround are typically installed from a centerline outward to ensure both end-cuttings match. At best, the interlocking features provide for three directions, but more typically only two. The only exception is a dovetail interlock with symmetric features on all sides. However, owing to the narrow grout joint typically required between adhered wall and floor tiles, this concept cannot be rendered into a practical design. For these reasons, grouted wall and floor tiles have not included interlocking features and still require secondary spacers during installation to provide spacing and alignment. Furthermore, interlocking features force the tiles into a rigidly aligned pattern, which does not allow for variations that might be present in the wall or floor surface. Therefore, for wall and floor tiles that are adhered to a surface and subsequently grouted, it is undesirable to have the tiles connect or interlock.
Brown (U.S. Pat. No. 2,490,577 and U.S. Pat. No. 2,490,577) disclosed a system of tongue and groove (or pin and eye) connectors for plastic tiles. These plastic tiles were widely installed in the 1950s and 60s, but had inherent problems. It was assumed that having the tiles tightly fitted, without a grouted gap, was sufficiently waterproof to avoid water infiltration to the supporting wall. This proved otherwise, as mildew quickly built up behind and between the tiles. Unidirectional assembly for the tongue and groove design meant that traditional symmetries of tiling could not be achieved. This lead to tiling jobs that looked unbalanced. In addition, repair of damaged tiles was not possible without damaging adjacent tiles in the pin and eye method of attachment owing to a failure to foresee that a closed-loop captured flush to the wall cannot be removed from a pin mate. Masanek (U.S. Pat. App. No. 2013/0086861) is essentially the same patent as Brown's U.S. Pat. No. 2,490,577.
In the meantime, considerable development and commercialization of interlocking floor tiling and strip-flooring systems has occurred. In all cases, the desired result of the interlocking connection was to have the tiles secured tightly together. Shirakawa (U.S. Pat. No. 5,972,655) disclosed a two-stage connection of which the first stage includes features that appear to allow the deckings to be assembled in four directions, but would not be possible to complete the second stage. His invention disclosed a hook feature on the side of a first decking that inserted into a receptacle on the underside of a second decking, by first passing through an opening in its lower side wall. He disclosed that the inclined upper surface of the hook facilitated insertion of the hook into the receptacle by having it remain in contact with a series of mating curved ribs on the inside wall above the opening in the second decking so as to guide it into the receptacle. Once fully assembled, the mating ribs increased the contact area with the inclined upper surface, which facilitated a tight engagement, and thus a tight and reliable connection between the two deckings. His full disclosure, including the secondary fixture to secure the deckings together, is consistent with having the second decking lifted slightly to allow the tip of the hook on the first decking to pass through the opening and then having the second decking pressed down lightly to allow the ribs to guide the hook into the receptacle, similar to the way most other interlocking tiling systems are assembled. Assuming for the moment that each decking is secured down after installation (as is the case with tiles adhered to a surface), by having the hook features of one decking pass under the mating decking, it is only possible to continuously assemble the deckings in three directions. There will always be the case in one direction, where the hooks on the two sides of the next decking cannot simultaneously get through the openings of the two adjacent secured deckings. Sjoberg (US-2003/0094230) disclosed an interconnecting means for strip-flooring, which ensured that the flooring was tightly interlocked. He discloses a continuous projecting feature on one edge, which can be rotated into a mating groove on the adjacent flooring. As with Shirakawa's invention, the projecting interconnecting feature on one flooring is covered by adjacent flooring, which would then not be a suitable means for allowing tiling to be assembled in 4 directions.